Scarfing burner tip



June 7, 1966 J. T. GRIMM 3,254,696

SCARFING BURNER TIP Filed Oct. 22, 1965 I NVENTOR. JOHN T. GEM/MATTORA/EKS.

United States Patent 3,254,696 SCARFING BURNER TIP John T. Grimm,Industry, Pa., assignor to Crucible Steel Company of America, acorporation of New Jersey Filed Oct. 22, 1963, Ser. No. 317,882 8Claims. (Cl. 15827.4)

and abrasion cause a very aggravated condition of wear on the lower sideof the burner tip which comes in contact with the billet.

Numerous efforts have been made to solve this problem by the use of ametal that is highly wear-resistant at high temperatures, but none ofthese proposed solutions have been satisfactory, primarily due to thefact that such metals are very brittle. One of the most common of theseexpedients involves surrounding the extreme end of the burner tip with aband of such metal. However, this solution has not been very successful,as the band has a tendency to erode and crack away quite rapidly.

The present invention provides a different solution. Instead ofsurrounding the tip of the burner with a band of wear-resistant steel, aband of copper-bronze is used, and projecting lugs of wear-resistantsteel are arranged on the periphery of this band. These wear-resistantlugs are carried by a ring of mild steel mounted on the burner tip. Bythis arrangement the copper-bronze band helps to dissipate the heat, andthe wear-resistant lugs can be located at the points where localizedabrasion takes place. With this arrangement the life of the burner tipis very much longer than when a solid band of wearresistant steel isused.

The invention also includes the special construction of the ring of mildsteel which carries the lugs of harder metal. This is the part ofapplicants device subject to most wear, and could conveniently bemanufactured and sold as a separate unit for the repair of the completedevice.

These, and other objects and advantages of the invention will becomeapparent as the description proceeds.

In the drawings:

FIG. 1 is a side elevation of a burner tip of the invention beingapplied to a billet.

FIG. 2 is an oblique side view partly broken away to show a prior-artdevice.

FIG. 3 is an exploded perspective view of the parts of the protectorband of the present invention.

FIG. 4 is an oblique side view of a scarfing burner tip incorporatingthe invention.

FIG. 5 is an end elevation of the burner tip of FIG. 4.

The scarfing burner includes the head which is carried at the end ofoxygen tube 11 and gas tube 12. The tip 13 is attached to head 10 by thecoupling nut 14 in a well-known manner. The tip 13 is provided with .arelatively large center bore 15 which conducts oxygen for the scarfingoperation and with a series of relatively small side bores 16 whichconduct oxygen and fuel gas, such as acetylene, for the pre-heatoperation.

It will be understood that the head 10 is provided in a well-knownmanner with suitable internal connecting passages to conduct the fuelgas from the tube 12, and oxygen from the tube 11 to the bores 16. Thehead 10 is also provided with suitable internal passages to conductoxygen from the oxygen tube 11 to the central bore 15. l

3,254,696 Patented June 7, 1966 "ice A scarfing operation using ascarfing burner tip of the type involved in this invention is performedby first using the oxy-acetylene flame to heat a portion of the billet17 to kindling temperature after which a jet scarfing oxygen is directedagainst the heated portion of the billet.

In carrying on the scarfing operation the s'carfing-burn-' er ismanually applied to the billet in approximately the position illustratedin FIGURE 1. Since hand scarf ing torches may be as much as four feetlong and weigh approximately twenty pounds, the operator usually permitsthe end of the tip to skid along the upper surface of the billet so thatmuch of the weight of the torch is carried by the tip. The operator thenslides the tip along the billet to scarf a certain area during a passalong the length .of the billet. After reaching the end of the billetthe operator must return to the starting part and in doing so he usuallyagain permits the tip of the burner to skid along the surface of thebillet.

It will be understood that the burner tip is subjected to the very highscarfing temperatures and this combination of high temperature, plus theabrasion resulting when the tip skids along the billet, provides a verysevere condition of abrasion along the bottom side of the burner tip. f

One prior solution to this problem is illustrated in FIGURE 2. In thisinstance a band 18 is attached to the end of the burner tip. The band 18has been made of a 'cobalt'base or a nickel-base alloy which is highlyresistant to wear. However, these alloys also contain large percentagesof chromium or tungsten and-while they are extremely hard, are alsoquite brittle.

It is not practical to form the burner tip 13 itself from suchwear-resistant metals because of the difiiculty of forming and machiningthese metals. It is, therefore, preferred to form the tip 13 ofcopper-bronze which can readily be formed with the necessaryconfigurations such as the small'passages-16. The use of the bronzematerial is also advantageous for this part because of its ability toconduct away some of the heat of combustion.

The result is that in the construction of FIGURE 2 the wear-resistantband 18 is subject not only to abrasion, but to the expansion of thebronze tip 13 and to entrapment of heat, with the result that there is atendency for this band to erode and crack away very rapidly, as shown bythe roughened surfaces in FIGURE 2.

The method of forming the protective band of the present invention isillustrated in FIGURE 3. The improved construction includes a band 19formed of copper-bronze similar to that of tip 13. This band 19 isformed with an inner diameter that fits closely over the outer surfaceof tip 13. v

A washer-like ring 20 which may be formed of mild steel has the sameinternal and external diameter as band 19. To this steel ring 20 areattached two lugs 21 which are formed of a highly wear-resistantmaterial as will presently be explained. The lugs 21 are welded (asindicated at 22) to the outer circumference of the ring 20 to form aring assembly.

In assembling the improved burner tip, the ring assembly is first placedover the tip, and the band 19 is then put in position. The assembly isthen subjected to a brazing operation which brazes these parts to eachother and to the burner tip 13, as indicated at 23.

It will be 'clear that the lugs 21 are of such axial length that theyextend over band 19, but do not project beyond the end of that band. Thelugs 21 may be of varied circumferential length, but it is preferredthat the two lugs together should cover approximately 20 to 40 percentof the circumferential extent of the band 19. .This is to avoid anyexcessive expansion stress of the ring 19 on the lugs 21.

In some cases it may be preferred to use only one of the lugs 21, ormore than two lugs, although a pair of lugs is the presently preferredconstruction.

The lugs 21 may be formed of any suitable high-temperaturewear-resistant material indicated in a descending order of preference asfollows:

I. Cobalt-base alloys Alloy Alloy A B II. N ickel-base alloys Alloy AAlloy B Alloy 0 Alloy D Alloy E 1.75/225 10 05 max 08 max 05 max .50max. 60 25.0/27.0 1 0 max 15. 5 22. 0 8.0/9.4 60 4. 0 .6 1.0 max. 18.505. 0 5. 0 17. 0 5 .30 max. 1. 50 2 5 max 2 5 max 2 5 max III. Hot-worktool steels Alloy A It has been found that low carbon (mild) steel istotally unsuitable for the lugs 21, because this material oxidizes anddisintegrates rapidly under operating conditions.

With the construction of the present invention, the bronze band 19,which is brazed to the tip 13, provides a good heat conduction path toconduct heat away from the burner tip without applying excessivepressures of expansion to tthe lugs 21. The lug 21 at the bottom side ofthe burner tip, as illustrated in FIGURE 1, provides a sled-runner typeof support for the burner tip, and after this lower tip becomes undulyworn the coupling nut 14 may be loosened and the burner tip 13 rotatedso as to bring the upper lug 21 into the lower operating position. Thesetwo spaced-apart lugs thus provide substantial wearresistant surfaces,while at the same time avoiding the difiiculties that cause rapiddeterioration of the complete band as in FIGURE 2.

The advantages of the present invention that provides a scarfing burnertip with a greatly prolonged life, will be evident to those skilled inthe art.

According to the provisions of the patent statutes, I have explained theprinciple of my invention and have illustrated and described What I nowconsider to represent its best embodiment. However, I desire to have itunderstood that, within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically illustrated anddescribed.

I claim:

1. In a scarfing burner of the type having a tubular (0 tip formed frommetal having relatively high heat conductivity, the improvement whichcomprises:

(A) a band formed of metal of relatively high heat conductivitysurrounding and brazed to the outer end of the burner tip;

(B) a ring formed of mild steel,

(1) the ring fitting over the burner tip, and

(2) being located adjacent the inner end of the band; and

(C) at least one lug formed of a hard metal having high resistance toheat and wear,

(1) the lug being welded to the steel ring to form a ring assembly,

(2) the ring assembly being positioned over the burner tip with the lugextending axially over .the outer periphery of the band,

(D) the ring assembly being brazed to the burner tip and to the band.

2. A device as specified in claim 1 in which a pair of lugs areprovided, the lugs being located on opposite sides of the band.

3. A device as specified in claim 2 in which the lugs together coverapproximately 20 to 40 percent of the periphery of the band.

4. A device as specified in claim 1 in which the burner tip and the bandare formed from copper-bronze.

5. In a scarfing burner of the type having a rotatable tubular tipformed from material having relatively high heat conductivity, theimprovement which comprises:

(A) A band of metal of heat conductivity comparable to that of theburner tip, the band surrounding and being brazed to the outer end ofthe burner tip, and

(B) a ring fitting over the burner tip and secured adjacent the innerend of the band, and

(C) a pair of lugs carried by the ring and adapted to contact theworkpiece being scarfed,

(1) the lugs being formed of a metal that is harder and morewear-resistant that the material of the burner tip, but of lesser heatconductivity than the band,

(2) the lugs being located on the upper and lower ends of a diameter ofthe burner tip,

whereby, when the lower lug becomes worn, the burner tip may be rotatedto bring the upper lug into the lower position where it may be broughtinto contact with the workpiece being scarfed.

6. A device as specified in claim 5 in which the lugs together coverapproximately 20 to 40 percent of the periphery of the band.

7. A device as specified in claim 5 in which the burner tip and the bandare formed from copper-bronze.

8. A protecting device for the tip of a scarfing burner, whichcomprises:

(A) a ring formed of mild steel and of a size to fit over the end of theburner tip; and

(B) a pair of lugs welded to the ring at opposite ends of a ringdiameter, and extending axially of the ring, the lugs being of a metalharder and having a higher resistance to heat and wear than mild steel.

References Cited by the Examiner UNITED STATES PATENTS 2,277,472 3/ 1942Anderson 158--27.4 2,282,397 5/1942 Deck 15827.4 X 2,337,087 12/1943Deck 15827.4 X 2,337,106 12/1943 Jacobsson 15827.4 2,356,196 8/1944Barnes et al. 15827.4 2,356,197 8/1944 Jones et al. 15827.4 X 2,510,2276/1950 Jacobson 15827.4 2,745,475 5/1956 Thompson et al. 15827.4 X3,091,281 5/1963 Clark 15827.4 3,112,883 12/1963 Blanchard 239-591 XFOREIGN PATENTS 181,091 2/ 1936 Switzerland.

JAMES W. WESTHAVER, Primary Examiner.

MEYER PERLIN, FREDERICK L. MATTESON, JR.,

Examiners.

V. M. PERUZZI, R. A. DUA, Assistant Examiners.

8. A PROTECTING DEVICE FOR THE TIP OF A SCARFING BURNER, WHICHCOMPRISES: (A) A RING FORMED OF MILD STEEL AND OF A SIZE TO FIT OVER THEEND OF THE BURNER TIP; AND (B) A PAIR OF LUGS WELDED TO THE RING ATOPPOSITE ENDS OF A RING DIAMETER, AND EXTENDING AXIALLY OF THE RING, THELUGS BEING OF A METAL HARDER AND HAVING A HIGHER RESISTANCE TO HEAT ANDWEAR THAN MILD STEEL.